This invention relates to the field of image printing, and more specifically to an apparatus, architecture and method for high-speed printing of digital image data onto a photo-sensitive substrate such as paper.
For many years, color photographs were produced in an analog process based on silver-halide chemistry. An image was captured by exposing a photo-sensitive film to a scene by a lens system in a camera. The photo-sensitive film was developed producing a dye image on the film. A photo-sensitive paper was in turn exposed to an image formed by the dye image on the film to generate a photographic print. Lens systems can be used to enlarge the image that is printed onto the paper substrate.
As with other systems, photography can benefit from digital techniques applied to various aspects of the process. However, it is still often desirable to retain certain aspects of prior technologies. Image data, captured by a digital camera or digitized from a reflective print or a film by a scanner, can be transmitted anywhere in the world almost instantaneously and then stored on mass storage devices. Multiple copies can be easily made and stored at multiple different sites. The image data can be manipulated using image-processing software systems. Ultimately, the digital image data can be printed on paper (or film or other substrate) to generate high-quality photographic images for viewing and sharing.
The digital image data are converted into a light pattern that is imaged onto a photographic paper that is processed using a conventional chemical process for color prints. Typically, the photographic paper, in the form of a long roll or a cut sheet, is exposed to form a series of latent images, then passed through the chemical processor in a continuous fashion. The roll paper is cut into individual prints. Conventionally, a stack of such photographic prints would be placed back into an envelope used to submit the film for processing. However, in the case of digital images that can be submitted across the internet, there is no such envelope, so one must be generated and addressed to the customer or recipient for the photos.
Image data are often compressed. To generate a print of such compressed images, one must uncompress the data and perform image processing on the uncompressed image data. The image processing operations can include tone or color adjustment, neutral balance, and image enhancement. The compression function is typically performed in a computer programmed with the algorithm needed to uncompress the data. If the uncompression and the image processing are not fast enough, this function can become a bottleneck, limiting the overall speed of the system.
The process for generating photographic prints includes a number of different subprocesses, such as preprocessing the image data, converting the image data into an image exposure pattern to expose a photosensitive material coated on a substrate to form a latent image, processing the photosensitive material to form a dye image, optionally printing on the back of each print, cutting and stacking the prints, and packaging and shipping the prints. Any of these processes can become a bottleneck that limits the overall speed of the system.
Thus, there is a need for a method and apparatus that can quickly reproduce photographic prints in response to a stream of input digital images.
The present invention provides a high-speed digital photographic printing system includes image-specific backprinting and automatic tracking and sorting of printed jobs. The high-speed digital photographic printing system includes a plurality of photographic printers, where each printer can have a different printing rate. A scheduler schedules printing orders to the different printers. The printer-independent image rendering is conducted asynchronous to the printing to maximize the printing throughput. In some embodiments, the rendering image processor does the vast majority of the image processing and outputs a printer-independent data file (generally much larger than the source image data file) that requires little if any further data manipulations or processing in the exposure unit.
One aspect of the present invention provides a photographic printing system for producing prints in response to input digital images. System includes a high-speed exposure unit that exposes a photosensitive material coated on a substrate in response to the input digital image, a chemical processor unit that receives and processes the exposed photosensitive material to form visible dye images on the substrate, a backprinting unit that receives the substrate having the visible dye images and prints information on the opposite surface of the substrate to the dye image, and a cutting unit that produces separate sheets of printed images after the backprinting unit prints information.
Another aspect of the present invention provides a method for high-speed photographic printing of input digital images onto a photosensitive material coated on a substrate. This method includes exposing the photosensitive material based on the input digital images, chemically processing the exposed photosensitive material to form visible dye images on the substrate, after the chemical processing, backprinting information on an opposite surface of the substrate to the dye image, and cutting the substrate to produce separate sheets of printed images, wherein the exposing is performed at an exposing rate, the chemically processing is performed at a processing rate and the exposing rate is different than the chemically processing rate.
Yet another aspect of the present invention provides a photographic printing system for producing prints in response to input digital images. This system includes a scheduler that receives digital images and scheduling the digital images to be exposed on different exposure units, a first exposure unit that exposes a photosensitive material coated on a substrate being in response to the input digital image scheduled by the scheduler, wherein the scheduler causes a first subjob of a single customer order to be exposed on the first exposure unit, a second exposure unit that exposes a photosensitive material coated on a substrate in response to the input digital image scheduled by the scheduler, wherein the scheduler causes a second subjob of the single customer order to be exposed on the second exposure unit, and a sorter unit that consolidates cut-apart prints of the first subjob and the second subjob into a single group of prints.
Still another aspect of the present invention provides a photographic printing system for producing prints in response to input digital images. This system includes a scheduler that receives digital images and schedules the digital images to be exposed at different exposure units, a print unit that exposes and develops a photosensitive material coated on a substrate being in response to the input digital image scheduled by the scheduler, a high-speed exposure unit that exposes a photosensitive material coated on a substrate in response to the input digital image scheduled by the scheduler, a chemical processor unit that receives and processes the exposed photosensitive material from the exposure unit to form visible dye images on the substrate, a backprinting unit that receives the substrate from the chemical processing unit having the visible dye images and prints information on the opposite surface of the substrate to the dye image, and a cutting unit that produces separate sheets of printed images after the backprinting unit prints the information. In this case, print unit both exposes and develops the prints, and optionally backprints, cuts and/or sorts the prints.
Another aspect of the present invention provides a photographic printing system for producing prints in response to input digital images. This system includes a plurality of photographic printer exposure units, an image cache, an image rendering unit that renders the input digital images and is operatively coupled to place the rendered images into the image cache. A scheduler is operatively coupled to the plurality of photographic printer exposure units, and schedules the rendered digital images from the image cache to be printed by each exposure unit, and an image processor associated with each printer for receiving the rendered digital images and processing the rendered digital images in accordance to the specific characteristics of the exposure unit, and such processed images being subsequently printed by the exposure unit.